The invention discloses a fermentation method of mulberry wine, and aims at solving the problem that the defects, such as difficulty in transportation of raw materials, high equipment investment and loss of nutrient substance, of the existing preparation method of the fermented mulberry wine restrict the development and the popularization of the mulberry wine to a great extent. The fermentation method comprises the following steps of: (1) pretreatment of raw materials; (2) preparation of seed solution; (3) fermentation. According to the fermentation method provided by the invention, the traditional fermentation technology of the mulberry wine is changed, during the preparation process, breaking and juicing processes to the mulberry are reduced as much as possible, so that the preparation technology of the mulberry wine is simplified effectively, the equipment investment is lowered, and the loss of the nutrient substance in the mulberry wine is avoided effectively. Meanwhile, by the fermentation method provided by the invention, the dry mulberry can be used as the raw material, which is convenient for transportation and storage of the mulberry, thus, the problem of waste of mulberry raw material caused by the delay of treatment to the mulberry is solved effectively.